The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 04, 2008
Filed:
Sep. 20, 2005
Kazushige Yokota, Ayase, JP;
Eiji Tsuruta, Yamato, JP;
Kazushige Yokota, Ayase, JP;
Eiji Tsuruta, Yamato, JP;
Nissan Motor Co., Ltd., Yokohama, JP;
Abstract
In a load-driving apparatus with a FET between a battery and a load, an overcurrent detection circuit has a function generation circuit with a voltage divider circuit and a comparator. The voltage divider circuit has a pair of resistors connected to a drain of the FET, and a Zener diode connected to a connection point in parallel to the second resistor. The comparator compares a reference voltage at the connection point with a variable voltage of the FET, and outputs an overcurrent detection signal when the variable voltage becomes lower than the reference voltage. When no overcurrent exists and the battery voltage is not decreasing, the connection point is kept at a breakdown voltage of the Zener diode, and the difference with respect to the source voltage of the FET becomes particularly large. The comparator therefore does not erroneously output an overcurrent detection signal even when noise enters the system.